Wheel brake device



March 26, 1940, c. c. FARMER y2,194,743Y

WHEEL BRAKE DEVICE Filed June 9, 1938 INVENTOR CLYDE C. FARMER BY lWW1/.49M

\ ATTORNEY `Patented Manzo, 194s UNiTeD( y STATES! PATENT OFFICE27,194,743 WHEEL BRAKEDEVIGE Clyde c. Farmer', Pittsburgh, Pa., ssignorto The WestnghouseAir Brake Company, Wil- :emerdingg Pa., a .corporationof Pennsylvania Application June 9, 193s, serial No. 212,825

s z claims. (01.105-194) 10 are supported longitudinally arrangedequalizing l bars carrying resilient vmeans including equalizer springswhich in turnzhelp to support the truck side-frame members. A .truckbolster is transversely mounted on the side frame members and l5` hasthe adjacent end of the car body secured,-

thereto by means of the usual center bearing mechanism, which mechanismis thuscarried a considerable distance above the axles. `Thisarrangement provides the necessary freedom for 20 relative motionbetween the wheels and the frame in' order that road shocks transmittedto the `car body will be minimized andin order also that the Vwheels mayfollownirregularities in the track. In a truck of conventional desigmthebrake shoes are hung from `the frame and are almost universally mountedbelow the center line of vthe wheels for reasons of clearance, andtoprevent `brake shoe pressurevirom forcing the journal out oi itsbearing. 30 It has been found that when thebrakes carried on a truckofthe above type areapplied to the wheels with great force while thevehicle is traveling at highspeed, resultant forces cause.

the frame members to be pulled downwardly with .5 respect to thewheels,` these forces being augmented on the forward `portion ofy thetruck by reason of the inertia ofthe car body acting through the mediumof the center bearing mechanism, and, in the case cina single shoebrake, by the drag of the shoes on the wheels. These extraordinaryforces act on the truck in such a manner as to cause the frame to tiltwith vrespect to the wheels, and mayeven cause the `forward. portion ofthe frame yto dip into con- 45 tact with unsprung members of the truck,thereby rendering the equalizer springs entirely ineffective to permitthe necessary play between structural membersof vthe truck. Undesiredresults oi. such overloading of the truck springs and 50 abnormaldisplacement of the frame members include not only hard riding in thevehicle and dangerous stresses on the truck members, but alsosuchvariance of the normal forces acting between the wheels and therails as may increase 55 the tendency of the wheels to slide. Y

One object of theinvention is` to provide an improved vehicle truckassembly including spring means eective normally to-permit the desiredflexibility and relative movement between Vun- `sprung wheel-carriedmembers and the sprung truck frame members, and rendered elective uponexcessive displacement ofthe frame members during a heavy applicationyof` the` brakes to yieldingly oppose further displacement.

Another object of my invention is to provide a compound equalizer springmeans for a vehcle truckhaving maximum resiliency during normaloperation ofthe truck for permittingy `the desired movement oi the truckframe with respect to the wheels and axles, but operative, l Whenhighbreaking forces tend to displacethe sprung frame relative to theunsprung wheelcarried members a predetermined degree, to resilientlyrestrict said relative movement between the frame and wheels, wherebyoverloading of the truck springs is prevented.

It is` a further object of myinvention to pro- `Vide a railway truckcomprising longitudinally disposed equalizing bars supported `on axlejournal boxes, a framesupported through the medium of the usualequalizer springs by said `equalizing bars, and auxiliary yielding`means carried on the truck in cooperative relation with said frame andequalizing bars, which means is ineffective to resist normal,substantially parallel movement of the frame with `respect to theequalizing bars, but becomes operative to oppose excessive-obliquangularmovement of said frame tending to overload the equalizer springs whenthe vehicle brakes are forcefully applied.

Other .objects and advantages willappear in the following" detaileddescription of theinvention, taken with reference to the accompanyingdrawing, wherein- Fig. 1 is an elevational view, partly inrsection, 4o`of a portion of a railway vehicle truck embodying one `form of myinvention; and Figs. 2 and 3 are elevational views of similar trucksembodying different forms of the invention, respectively.

Referring to the drawing andrparticularly to Fig. 1 thereof,` there isillustrated in simplined` form a portion of a railway truck, including awheel and the associated elements of the adjacent end of the truck, itbeing understood of course (that the completetruck is of the type havingat least four wheels. Although the truck may be of anysuitableconstruction, it is illustrated in a design suitable `for a` passengercar and comprises a truck frame 5 having spaced side frame members, oneof which is designated 5, and which are connected together by the usualtransversely disposed transoms, not shown. Pedestal jaw members 'i aresecured to the side frame members 6, and have slidably guided thereinthe usual journal vboxes 8 associated with the bearings of the wheel andaxle assemblies 3. For carrying each of the side frame members 6, thereis provided a longitudinally disposed equalizing bar il having at eachend a suitable offset portion I 2 in rocking engagement with the uppersurface of the corresponding journal box B, and having secured theretoadjacent each oiset portion a spring seat Ili upon which rests the usualequalizer spring l for supporting the truck frame. In addition toequalizer springs i5, of which there are usually Tour, there may beprovided suitable elliptic springs, not shown, mounted intermediate thewheel and axle as semblies, or to the left of the wheel 9 as shown inFig. 1.

'The usual braking means may be provided, including a brake shoe ivadapted to be applied to the wheel 9 below the center line thereofthrough the medium of a brake rigging apparatus, not shown. The brakeshoe il is supported by means or" a brake shoe hanger I8, the upper endof .which is pivotally connected to the side frame member 6. A

According to my invention, the'equalizing bar II is provided at each endwith a prolongated portion or arm 2li, which extendsllongitudinally andin parallel alignment with the adjacent end portion 2 i, of the truckframe 6. It will be noted that the portion of the equalizing bar ilinter mediate the arm 23 and the bearing portion I2 is inclineddownwardly so that the arm 2611s spaced from the portion 2i of the truckframe, as shown in the drawing.

The arm 2B of the equalizing bar has formed therein a verticallydisposed bore 23, through which is slidably mounted one end of aplunger- 2li, which extends vupwardly from the'armI 28 and carries abuiier member 25 in operative alignment with the lower surface of theframe portion 2i. A coil spring 26 is disposed around the plunger Ellbetween the member 25 and a depressed surface 2 of the arm 2li forurging the plunger upwardly. The plunger 28 is held in place and thespring 2% may be suitably tensioned by means of a nut 28, which isapplied to the threaded portion of the plunger extending below the arm2li, and which is adapted normally to engage the lower surface ofthe armas shown in the drawing. There will thus be such an auxiliary springmechanism at each of the four corners of the truck.

In operation, assuming that the vehicle is moving toward the right-hand,if the brakes are applied with normal force, the truck frame 6 is notdeflected appreciably with respect to the unsprung members of thevehicle'truck by the braking forces, Iso that the truckl springsincluding the equalizer spring i5 remain effective resiliently tosupport the weight of the truck frame and Vehicle body in the usualmanner, it being understood that sufficient clearance is providedbetween the end 2l of the truck frame and the buffer member 25 to allowfor normal undulating motion 'of the truck frame with respect to theequalizing bar Il.

Ii, however, the brakes should be applied with maximum force while thevehicle is moving at a relatively high speed toward the right-handdirection, theV momentum of the vehicle body, actingV through the mediumof the truck center vrof the truck frame 6.

`engagement with the shoulder 35.

bearing, may be suiicient to cause tilting of the truck frame 6 beyondthe desired range of movement, as already explained. In thus tiltingdownwardly, the forward end 2l of the truck frame 6 engages the twoforward buler members 25, and further downward movement of the truckframe is then resiliently resisted by the force of the two forward coilsprings 26, which act simultaneously with the equalizer springs i5 butat greater advantage than those springs by reason of the considerableleverage distance between the end 2l of the truck frame 6 and the centerbearing thereon, not shown in the drawing. It will thus be seen that theextraordinary forces tending to displace the truck frame more than apredetermined degree with respect to the equalizing bar and otherunsprung members are substantially absorbed by the pair of auxiliarysprings 26 at the forward end of the truck, so that hard riding of thevehicle and possibly dangerous strains upon certain of the truck membersare prevented.

Referring to Fig. 2 of the drawing, `the miodied form of my inventionshown therein is embodied in a railway truck of the same type as thatshown in Fig. l. In this form of the invention, the auxiliary yieldingmechanism is adapted to resist either downward or upward displacement ofthe end of the truck frame to which it is applied, when suchdisplacement exceeds a predetermined degree. As shown in Fig. 2, the armof the equalizing bar I I has formed therein a bore 30 which is disposedin vertical alignment with a bore 3| provided in the end 2l Extendingthrough both of the bores 3|] and 3l is a vertically disposed springhanger rod 33, which has secured to the upper end thereof a nut 3dengaging the upper surface of the truck frame 6 for holding the rodagainst downward movement. The portion of the rod 33 intermediate theends thereof and normally disposed within the bore 3G is enlarged toform annular shoulders 36 and 3l, each of` which shoulders extends asuitable distance outwardly ofthe bore 3@ as shown in Fig. 2.

Slidably mounted on the hanger rod 33 intermediate the arm 2G of theequalizing member II and the end portion 2l of the truck frame are apair of annular spring seats 39 and dil, which have interposedtherebetween a coil spring I that is adapted to urge the seat 39 intoengagement with the portion 2l and the seat t@ into it will be notedthat the annular seat #it is thus normally spaced above the uppersurface of the arm 20.

Similarly, a coil spring 43 is mounted on the portion of the hanger rod33 extending below the arm 26, the spring being interposed between anannular seat 44 normally engaging the shoulder 31 and an annular seat l5which is held in engagement with a nut 46 having screw threadedconnection with the lowermost portion of the rod 33. The spring seat deis thus normally held a suitable distance below the lower surface of thearm 20.

It will thus: be apparent that when the vehicle is operating under usualconditions, the weight of the vehicle body carried by the truck 5 isresiliently supported by means of the standard truck spring apparatusincluding equalizer spring I5, while the auxiliary springs I and i3 ateach of the four corners of the truck are maintainedv inactive by reasonof the clearance providedy between the vequalizing arm 20 and therespective seats 4l? and 44, which clearance perwhile the vehicle truck5 is traveling in a righthand direction as viewed in Fig. 2, and thetruck frame 5 is vthereby tilted beyond the normal range of movementthereof, the forward end 2| of the frame is brought downwardly towardthe arm 2|] of the equalizing bar il while the truck spring apparatusincluding the equalizer springs I5 is overloaded, by reason of theextraordinary forces produced as the speed of the vehicle is thussuddenly decreased, as alreadyv explained. As the forward end 2l of thetruck frame is thus forced downwardly, the hanger rod 33 is therebycarried in the same direction so that the spring seatel is brought intoengagement with the arm 20 of the equalizing bar Il. Further movement ofthe truck frame toward the equalizingr bar is then resisted by theauxiliary spring il acting together with the truck springs, such as theequalizer springs l5, for resiliently limiting the amount ofdisplacement of the truck frame members with respect to the unsprungelements of the truck. At the same time, this action of the spring 13|mounted on the forward portionvof the vehicle truck as shown in Fig. 2

in resisting obliquangular displacement of the truck. frame 5 is aided,in the present embodiment of the invention, by similar action of springscorresponding to the springs 43 of Fig. 2 but carried on the opposite orrear portion of the vehicle truck, as `will be understood from thefollowing explanation.

, Assuming that the portion of the vehicletruck shown in Fig. 2 is therear portion, or in other words that the vehicle is traveling toward theleft, when the truck frame 5 is tilted as a result of a heavyapplication of the brakes the end portion 2l will this time be movedupwardly and away from the arm 25 of the equalizing bar Il. `The hangerrod 33 is thereby lifted until the spring seat M is brought intoengagement with the lower surface of the arm 2li of the equalizing bar.The spring 43 is then effective to oppose i further upward movement ofthe truck frame 6 and rod 33, in cooperation with the spring 4I at theforward end of the truck as hereinbefore explained` Infthis embodiment,therefore, undesired tilting action of the truck is resisted at both thefront and rear ends of the truck.

Referring to Fig.` 3 of thek drawing, the third embodiment of theinvention therein illustrated comprises an auxiliary spring mechanismadapted to operate in amanner similar to that of the embodiment sho-wnin Fig. 2 for preventing-excessive displacement of the adjacent end ofthe truck frame either upwardly or downwardly. The spring mechanismshown in Fig. 3 comprises a single coil spring 50 interposed between anannular spring seat 5l and an annular spring guide plate 52, which areslidably mounted on a vertically disposed bolt 53 havingthe lowerportion thereof extending through a suitable bore 54 formed in the arm20 of the equalizing bar. The bolt 53 has a head 55 engaging the guideplate 52, and is provided with a nut 5l which has screw-threadedconnection with the portion of the bolt extending beyond the arm 20 andengages the lower surface of the arm for a limiting upward movement ofthe plate 52.

Secured to the portion of the frame above the arm 20 of the equalizingbar is a buffer member 59, which has an' elongate bolt portion 60extending through a suitable bore formed in the portion 2l and rigidlyvsecured thereto by means of a nut 6I.

The member 59 has a pair of shoulders 62 disposed in alignment withtheplate member 52, which is adapted to engage the shoulders when the frame6 is moved downwardly beyond a predetermined range. For limiting upwardmovement ofthe frame S with respect to the equalizing bar, the buffermember 59 has formed thereon two leg portions terminating in inwardlyturned lugs 64, which extend into suitable recesses or slots 65 formedin the arm portion 20 of the equalizing bar, As shown in the drawing thelugs 64 are aligned with the lower surface of spring seat 5I, and arenormally spaced from the seat for permitting a certain v range of upwardmovement of the truck frame l with respect to the equalizing bar freefrom any opposing force of the auxiliary spring 50.

The operation of the device shown in Fig. 3 will be understood from theforegoing description of the other embodiments of the invention. It willthus be seen that excessive downward movement of the end 2l of thetruckframe 6 will cause engagement ofV the shoulders 62 of the buffermember 59 with the spring plate 52so that further movement will beresisted by the force of the spring 50. Similarly excessive upwardmovement ofthe truck frame E with respect to the unsprung portion of thetruck will bring the lugs 54 into engagement with the lower spring seat5I, which is adapted for resilient `upward movement along the bolt 53against th force of the spring 55.

It will be apparent from the foregoing description that auxiliary springmechanisms oonstructed in accordance with the invention may be mountedon the ends of a railway truck without necessitating materialalterations in' the structural members thereof, and that the auxiliaryspring means will effectively resist excessive displacement of the truckframe due to high braking forces, while remaining inactive when thevehicle truck is operated under normal conditions and while the truckframe is adequately supported by the usual truck springs, including therelatively soft equalizer springs.

Having now described my invention, what I claim as new and desire tosecure by Letters nal boxes guided by said pedestals, longitudinallydisposed equalizing bars supported on the journal boxes at each side ofthe truck and having pro-longated arms extending longitudinally beyondsaid journal boxes at the ends of the truck and in alignment with theadjacent ends of saidV follower members operatively mounted on theprolongated arm of the equalizing bar, a spring vertically interposedbetween said follower members, and a buffer member secured to said framein operative alignment with said spring and having a shoulder normallyspaced above one of said follower members and `depending arm porfollowermembers operatively mounted on the arms of said unsprung frame part, aspring vertically interposed between said follower members, and a buffermember secured to said sprung frame part in operative alignment withsaid spring and having a shoulder normally spaced above one of saidfollower members and depending arm portions stradclling said spring andterminating in lugs spaced beneath said other follower member.

CLYDE C. FARMER.

